脉冲激光诱导金属薄膜电离的分子动力学模拟  

Molecular dynamics simulation of pulsed laser induced ionization of metal thin films

作　　者：李成祥 李凌[1] LI Cheng-Xiang;LI Ling(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《原子与分子物理学报》2022年第2期105-111,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(51476102)。

摘　　要：采用分子动力学方法模拟研究了激光诱导金属薄膜的电离过程,对激光等离子体形成早期原子的运动轨迹、薄膜表面的温度变化以及原子的电离特性进行了详细分析,并探究了脉冲激光参数对原子电离过程的影响.结果表明,在激光照射过程中,薄膜表面先熔化而后又气化,气化的原子继续吸收激光能量继而电离.激光的峰值功率密度越大,原子电离速率越快,电离数目越多,薄膜表面的温度越高.脉冲宽度越小,原子电离速率越快,薄膜表面的温度越高,但原子的电离数目先增加后减小.Molecular dynamics method is used to simulate the laser induced ionization process of the metal film. In the early stage of laser plasma formation, the trajectories of atoms, the temperature changes on the film surface and the ionization characteristics of atoms are analyzed in detail. Then, the influence of pulsed laser parameters on the ionization process of atoms is explored. Results show that when the laser irradiates the surface of a metal film, the film surface is melted and then vaporized. The vaporized atoms continue to absorb laser energy and then ionize. The higher the peak power density of the laser is, the faster the ionization rate of atoms on the surface of the film is, the greater the number of atoms ionization is, the higher the temperature of the film surface is. The smaller the pulse width is, the faster the atomic ionization rate is, the higher the temperature of the film surface is, but the atomic ionization number increases first and then decreases.

关 键 词：脉冲激光 原子电离 分子动力学 激光等离子体 

分 类 号：TN249[电子电信—物理电子学]